My loft's plumbing ?

[vfro]

Good Morning Everyone,


I'm trying to understand the plumbing I've got in my loft. The thing is that I don't get why there is a bypass from the cold water supply.

Here is how it goes in the picture : at the top, from the mains, then to the cold water supply in the flat, to an expension vessel and the bypass, and lastly down to the electric boiler.

Would anybody be able to take a few minutes and help me understand this please ?

Many thanks.

[gas4you]

That's not a bypass. It is the cold water pressure relief valve, usually at 6 Bar, teed into the temperature/pressure relief valve pipe that then goes into a tundish.

If either of these open you have a problem somewhere.

[vfro]

Thanks Dave,


Glad to have some new words for my home made Frenglish.

What I'm still wondering though is why this pressure relief valve would be needed on the cold water pipes.

Vincent

[gas4you]

It’s to protect the cylinder/system from the chance of too high mains pressure.

[vfro]

Merci !